Tesla Powerwall is the most requested home energy storage device by consumers, according to a new survey of solar installers.

The problem is that most of them can’t get Tesla’s home battery pack.

According to a new survey of solar installers by EnergySage, the majority of buyers asking for a home battery solution are requesting a Tesla Powerwall.

That said, the same report says that only 12% of the installers are able to carry and quote Tesla’s home battery pack:

“According to installers, more than one in three solar shoppers are also interested in a home battery, resulting in more solarplus-storage installations in 2018. However, responses also illustrate a gap between consumer brand preference and what installers stock. While over 55% of installers reported that their customers specifically request Tesla battery solutions, only 12% of solar installers surveyed actually carry and quote the Tesla Powerwall.”

While people want to buy a Tesla Powerwall, they often have to settle on other brands because Tesla can’t produce enough battery packs:

The reason why Tesla couldn’t capitalize on that demand is likely the fact that the Model 3 production ramp-up has taken over some of the company’s stationary energy storage production capacity.

CEO Elon Musk said during Tesla’s last earnings call:

“We would have done more in stationary storage last year except we were so strung for vehicle production. We had to convert a bunch of stationary storage lines, battery lines, to vehicle battery lines. Otherwise, we would have done quite a bit more in stationary storage.”